The present disclosure relates to the fields of vibration control and energy dissipation through a field-controllable fluid device. Particularly the present disclosure relates to a magnetorheological fluid control valve.
Magnetorheological fluid-based control valves provide flow control by varying electrical current to an electromagnet that affects the apparent viscosity of the magnetorheological fluid (MRF). Increased electric current provides an increased magnetic field, which in turn, increases the apparent viscosity of the fluid. Therefore, the flow rate through the valve can be controlled.
A MRF consists of ferrous particles suspended in a carrier fluid. The rheological behavior of the fluid occurs under presence of a magnetic field where the ferrous particles polarize to a chain-like formation. The iron particles chain up through attraction in the direction of the magnetic flux and the strength of their attraction is directly related to the strength of the magnetic field. The rheology of MRF is capable of changing within milliseconds under a magnetic field. MRF based valves are ideal for semi-active control applications.
MRF valves can be used in variety of mechanical systems such as automotive, bicycle, and motorcycle shock absorber applications, where damping forces are controlled. An emerging application for MRF valved dampers, as protective devices, is in the area of energy mitigation for large structures, such as buildings and bridges under earthquake and/or severe storms. These damper applications along with basic flow control in any hydraulic system comprise the primary fields of use for the invention.
State-of-the-art in MRF valve technology relies on strict manufacturing tolerances and additional mechanical assembly features that limit the practical application for a broad use in hydraulic systems. Designs that require electromagnetic solenoid locations close to the MRF valve region can make manufacturing and assembly cost prohibitive and prone to maintenance complications. MRF valves that require additional springs, pistons, and seals present additional potential valve wear induced failures. The magnetic field conduction path should be designed to prevent the least leakage of magnetic field to valve components that are not directly related to the MRF valving location.
The disclosure describes a magnetorheological fluid control valve. The magnetorheological fluid control valve comprises an electromagnetic coil having a first end and a second end. A first arm is magnetically coupled to the first end of the electromagnetic coil. A second arm is magnetically coupled to the second end of the electromagnetic coil. The second arm has a passage. A ferromagnetic rod having a diameter less than that of the passage is disposed in the passage and magnetically coupled to the first and second arms. A first manifold is coupled to the second arm at one end of the passage. A second manifold is coupled between the second arm and the first arm at an end of the passage opposite the first manifold. A magnetorheological fluid is disposed in the passage.